import cv2
import numpy as np
from registry import registry

@registry.register("Original")
def original(image):
    return image

@registry.register("Grayscale")
def grayscale(image):
    return cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)

@registry.register("Gaussian Blur", defaults={'kernel_size': 15}, min_vals={'kernel_size': 3}, max_vals={'kernel_size': 31}, step_vals={'kernel_size': 2})
def gaussian_blur(image, kernel_size: int = 15):
    return cv2.GaussianBlur(image, (kernel_size, kernel_size), 0)

@registry.register("Pencil Sketch")
def pencil_sketch(image):
    gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    inverted = cv2.bitwise_not(gray)
    blurred = cv2.GaussianBlur(inverted, (21, 21), 0)
    inverted_blurred = cv2.bitwise_not(blurred)
    return cv2.divide(gray, inverted_blurred, scale=256.0)

@registry.register("Sepia")
def sepia(image):
    kernel = np.array([
        [0.393, 0.769, 0.189],
        [0.349, 0.686, 0.168],
        [0.272, 0.534, 0.131]
    ])
    return cv2.transform(image, kernel)

@registry.register("Edge Enhance", defaults={'intensity': 1.5}, min_vals={'intensity': 0.5}, max_vals={'intensity': 5.0}, step_vals={'intensity': 0.1})
def edge_enhance(image, intensity: float = 1.5):
    kernel = np.array([
        [-1 * intensity, -1 * intensity, -1 * intensity],
        [-1 * intensity,  9 * intensity, -1 * intensity],
        [-1 * intensity, -1 * intensity, -1 * intensity]
    ])
    return cv2.filter2D(image, -1, kernel)

@registry.register("Canny Edge", defaults={'lower_threshold': 100, 'upper_threshold': 200, 'convert_to_gray': True}, min_vals={'lower_threshold': 0, 'upper_threshold': 255}, max_vals={'lower_threshold': 255, 'upper_threshold': 255}, step_vals={'lower_threshold': 1, 'upper_threshold': 1})
def canny_edge(image, lower_threshold=100, upper_threshold=200, convert_to_gray=True):
    if convert_to_gray and len(image.shape) == 3:
        gray = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY)
    else:
        gray = image
    edges = cv2.Canny(gray, lower_threshold, upper_threshold)
    return edges